Automatic blade control device for blade type earth moving machinery



1963 E. T. SMALL 3,077,682

AUTOMATIC BLADE CONTROL DEVICE FOR BLADE TYPE EARTH MOVING MACHINERY Filed Oct. 2, 1961 a Sheets-Sheet 1 INVENTOR. f/c'azrr [17/1044 Feb. 19, 1963 E. T. SMALL 3,077,682

, AUTOMATIC BLADE CONTROL DEVICE FOR BLADE TYPE EARTH MOVING MACHINERY Filed Oct. 2, 1961 a Sheets-Sheet 2 5O m 5 66 x 6 I F G 2 4 742 760 in. Z.

I as 5 3 782 c 1/6 84 68 5 F I I K 68 W 5 2 I I q F 4 200 36 I72 Z06 208 2/0 2/2 [6'6 760. 7.5; [64 I68 4 INVENTOR. /20 /30 92 96 82 72 74 66 775%,

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'Feb. 19, 1963 E. 'r. SMALL 3,077,682

AUTOMATIC BLADE CONTROL DEVICE FOR BLADE TYPE EARTH MOVING MACHINERY Filed 001:. 2, 1961 8 Sheets-Sheet 3 J /a4 68 Q 75%% -5 1 W INVENTOR.

F I I A i t I 6 8 m2 Q 784 2 i/EKITT 77541441.

72 7/ r 6 6 BY 1 Li 1 A.

Feb. 19, 1963 E. T. SMALL 3, 7 3

AUTOMATIC BLADE CONTROL DEVICE FOR BLADE TYPE EARTH MOVING MACHINERY Filed Oct. 2, 1961 8 Sheets-Sheet 4 234A TJ INVENTOR. 51 52: 7'. 5/1444 Arman-vs.

Feb. 19, 1963 SMALL AUTOMATIC BLADE CONTROL DEVICE FOR BLADE TYPE EARTH MOVING MACHINERY Filed Oct. 2, 1961.

8 Sheets-Sheet 5 5 20 'faad I (330 I (326 INVENTOR. [375F517 T 5/7,

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Feb. 19, 1963 E. T. SMALL 3,077,682

AUTOMATIC BLADE CONTROL DEVICE FOR BLADE TYPE EARTH ovmc MACHINERY Filed Oct. 2, 1961 8 Sheets-Sheet 6 INVENTOR. 5/525 7117/1941.

Feb. 19, 1963 E. r. SMALL 3,077,582

AUTOMATIC BLADE CONTROUDEVICE FOR BLADE TYPE EARTH MOVING MACHINERY 8 Sheets-Sheet 7 Filed Oct. 2, 1961 WNW INVENTORV EVE/arr T 5/7/7461 finer/mas.

Feb. 19,- 1963 L- E. -r. SMALL 3,077,532

AUTOMATIC BLADE CONTROL DEVICE FOR BLADE TYPE EARTH MOVING MACHINERY A Filed Oct. 2, 1961 '8 Sheets-Sheet 8 m a m L] \l INVENTOR.

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United States Patent 3,tl77,632 AUTUMATEQ BLABE (IUNTRQL DEWCE FGR BLADE T's 19E EARTH MQVlhIG MACHENERY Everett ll. Small, 2- 95 S. @range Grove Ave, Los Angeles, Calif. Filed Get. 2, 1961, Ser. No. 142,313 1i) Claims. (ill. 37-443) and supported by wheels or crawler tracks whereon a blade is mounted in front of the ground supporting members as in a bulldozer type of apparatus.

During an earth or material blading operation, the operator may desire to increase or decrease the depth of blade cut. blade of FIG. 1, it is necessary, when increasing the depth of blade cut, to first lower the blade to the desired depth, then raise it above the normal grading position as the machine progresses and then again to lower the blade to the proper grading position to maintain a smooth plane of cut. When decreasing the blade cut, the blade is adjusted in the opposite direction. The amount of vertical adjustment, the timing of making the blade adjust ment and the speed rate of the vertical adjustment are all extremely critical for obtaining a smooth plane of blading in all operations where it is necessary to adjust the cutting lade while the machine is in travel motion.

Manually controlled blades require a highly skilled machine operator to perform the exacting requirements for obtaining a smooth out in the longitudinal plane and can be accomplished only at a relatively slow vehicular travel speed.

The subject device provides:

True cutting in the longitudinal planeand on a parallel to the cut at the instant of blade adjustment.

Performance at a vehicular travel speed much faster than it is possible with manual controls because of the blading speed being restricted by the operators physical ability, experience and judgment.

One of the objects of the invention is to provide earth blading apparatus which is provided with raising and lowering means capable of moving the blade generally vertically between certain maximum grading limits, where in a control device is provided which can be readily trig gered or started by the operator when making a blade adjustment. This control device will then proceed through a cycle of movements of the blade vertically relative to the frame to compensate for the change in plane of the wheels or the endless tracks or" the vehicle from the plane or level of travel prior to blade adjustment to the subsequent plane or level after the blade is adjusted. The control device is such that the initial step or movement in the blade compensating action is controlled "by the operator and the succeeding movement or movements which constitute a cycle or adjustment will be carried on with preciseness under the direction of the control device.

One of the features of the control device is the ability, through a starter mechanism, to vary the initial movement in the cycle of compensating blade movements and to provide a control means which Will complete the cycle in increments of maximum grading limits of movement which are proportional not only to the initial degree of movement in the cycle but are also proportional to the forward location of the blade relative to the supporting Due to the forward mounting of the dozer 3,@7?,b82 Federated Feb. 19, 1963 "ice wheels, tracks or shoes, the latter three elements being referred to hereinafter as ground engaging means.

Another feature of the device is the ability to raise the blade automatically when the blade encounters an overload. Whenever the load imposed on the vehicle increases sufficiently to cause the engine to slow down from its governed operating speed setting, the control device automatically will cause the blade to raise sur'liciently to relieve itself of the overload and enable the tractor engine to regain its governed operating speed and at the same time initiate a subsequent cycle of blade adjustments.

The above and other objects will more fully appear from the following description in connection with the accompanying drawings.

FIG. 1 is a perspective view of a wheeled tractor and bulldozer with an embodiment of the invention mounted thereon.

FIG. 2 is a plan view of the gauge box for the blade compensating means with a portion of the box removed.

FIG. 2A is a fragmentary view taken approximately on the line AA of FIG. 2.

FIG. 2B is a fragmentary view taken approximately on the line E--B of PEG. 2.

FIG. 2C is an enlarged fragmentary detail in vertical section along line CC of FIG. 2 of a spring pressed ball unit for yieldably holding relatively movable parts.

H6. 3 is a transverse vertical section taken approxi mately on the line 3-3 of KG. 2.

FIG. 4 is a view similar to FIG. 2 with portions of the control mechanism in position for vertical blade adjustment in one direction.

FIG. 4A is a fragmentary view taken approximately on the line A-A of FIG. 4.

FIG. 4B is a fragmentary view taken approximately on the line BB of FIG. 4.

FIG. 5 is a view similar to FIG. 2 with portions of the control mechanism in position for vertical blade adjustment opposite to that shown in FIG. 4.

FIG. 5A is a fragmentary view taken approximately on the line A--A of FIG. 5.

FIG. 5B is a fragmentary view taken approximately on the line Bl3 of MG. 5.

FIG. 6 is a plan view partially in section of the control starter for the blade compensating control mechanism with the housing cover removed.

FIG. 6A is a side elevational detail of a rocker bar switch arrangement.

FIG. 7 is a sectional view generally along the line 77 of FIG. 6.

FIG. 8 is a side elevational view of the tractor valve lever regulator adjusted in the position for the blade lowering cycle.

FIG. 9 is an end elevational view of the structure shown in FIG. 8.

FIG. 10 is a view partially in horizontal section and partially in plan of the timing device for the control mechanism.

FIG. 11 is a View partially in vertical section taken approximately on line ll1l of FIG. 10.

MG. 12 is a partially diagrammatic view of a typical engine governor with control switches attached.

FIG. 13 is a diagrammatic view of the control mechanism and its electrical circuits.

MG. 14 is a diagrammatic view of a hydraulic type of blade vertical speed regulator.

FIG. 15 is a perspective view of a tractor dozer with another embodiment of the invention of blade control mounted thereon.

MG. 16 is a diagrammatic view of an auxiliary power actuating mechanism for the tractor valve lever.

in FIG. 1 there is shown an adaption of my invention to a bulldozer type of blade mounted on a wheeled tractor,

3,0 vsyeea it being understood that it adapts in like manner to an angle blade type dozer or to a crawler type tractor equipped with either types of blades mentioned above. The tractor is shown with rear wheels 12 and front wheels 14. A dozer blade 16 is attached to push beam members 19 connected to a tractor cross member 26. There is shown one of a pair of blade raising and lower. ing cylinders 22 with complementary piston rods 24 which are respectively connected to the forward end of the tractor 1t) and an inner member 18 of push beam member 19 (the far side not being shown). The tractor engine governor is indicated diagrammatically at 26.

Mounted on the tractor 10 is a timer unit which is shown having a drive wheel 32 urged against one of the rear ground wheels 12. Also mounted on the tractor is a gauge control assembly 36 actuated by means of a cable 38 which is supported at the forward end of the tractor by a sheave 40, the forward end of the cable being fastened to inner member 13 of push member 19. A switch panel 42 containing control switches for the mechanism is mounted on tractor 141 in a location convenient to the operator.

A starter control assembly 46 is shown mounted on tractor 10 with an operators starter lever 48. A blade speed regulator 56 for regulating the movement of a tractor valve lever 56 is connected to starter lever 43 by means of a rod 53. Tractor valve lever 56 actuates a tractor hydraulic valve 69 which controls the movement of the blade lift cylinders 22 on manually controlled dozers. Valve solenoids 62 and 64 are shown mounted on the hydraulic valve 6% for performing vertical adjustment of blade 16 in the operation of this device. The starter control lever 48 is suitably connected with the tractor hydraulic system and with other mechanism to be described below for initiating and controlling the interval of incremental vertical movement of the blade 16 to cause the blade to compensate vertically for the variations in elevation of the tractor 10 relative to a ground elevation at which the working edge of the blade 16 is intended to operate.

The prime functions of the major assemblies described in this invention are as follows:

The starting lever assembly 46, 48 starts and controls the initial blade adjustment and simultaneously establishes the vertical speed of the blade for the duration of the cycle.

The timer unit 31) activates the blade re-adjustment at the proper time during the cycle necessary for a smooth blade cut.

The. gauge control assembly 36 determines the amount of blade movement needed in re-adiustrnent operations during the cycle and stops the blade vertical movement when the proper amount of travel has been reached.

The relationship between the starter control lever 48 and other control mechanism will be brought out below.

Gauge Control Box FIG. 2 shows the gauge control assembly box 36 of FIG. 1 having a cable rod 37 and gauge cable 38, the gauge box and its enclosed mechanism being shown in FIG. 2 in a plan view. In FIG. 3 the gauge box 36 is shown as a transverse vertical sectional view. The outer end of cable rod 37 is connected to the cable 33 shown in FIGS. 1, 2 and 15 and the other end is connected to a switch plate 66 which is slidable in guides 68, 69 shown in the sides of the gauge box .36 in FIG. 3. A tension spring 79 is fastened to a switch plate 66 and to gauge box 36 for maintaining tension on cable 38. The switch plate 66 carries a pair of switches 72 and 74 at one end of the medial portion thereof and an oppositely positioned pair 76 and 73 shown in PEG. 2B. The switch plate 66 also carries a pair of switches 5% and S2 at one sidethereot and another pair of switches 84 and 86 at the other side shown in FIG. 2A. The switch plate 66 as best shown in FIG. 2 alsocarries oppositely disposed limit switches 92 and 94. Shown in PEG. 2 are two plate extensions 1'32 and 104 on switch plate 66 with opposing springs 1116 mounted thereon which anchor to bracket 168 shown in FIG. 3 for centering a sliding gauge frame with respect to switch plate 66.

At the approximate center of switch plate 66 is mounted a spring ball mechanism 96 (FIG. 2C, also FIGS. 2 and 3) enclosing a spring $8 pressing a ball 1% outwardly which engages a notch 101 of sliding gauge frame 116 and centers the gauge frame 116 with respect to the switch plate 66. A vertical bar 112 is mounted on switch plate 66 at right angles for spacing gauge arms 114 and 116 mounted on gauge assembly 116 during the initial adjustment of dozer blade 16 of FIG. 1.

A supporting rod 120 secured at both ends in housing 36 has a sliding block 122 shown in FIG. 3 mounted thereon which is a part of gauge frame 110. Extending from block 122 at right angles to the supporting rod 129 is sliding plate 124 the outer end of which slides in a groove provided in side plate 69. Mounted on the sliding plate 124 is a switch contact plate 126 which is part of gauge frame 110 and contains the centering notch 161 shown in FIG. 2C. On plate 124, as shown in FIG. 3, is mounted a solenoid 13%} for locking the sliding plate in operation which will be explained later. The solenoid 130 actuates a lever 132 on a hinge pin 134 which is mounted on the sliding plate 124 as shown in FIGS. 2 and 3. Also mounted on the sliding plate 124 is a bar 1.36 shown in FIG. 3 for actuating limit switches 92 and 94. On the opposite side of plate 124 is mounted a bracket 138 and a hinge pin 14% on which is mounted a pair of gauge arms 114 and 116.

Mounted on the sliding block 122 opposite the sliding plate 124 is a guide plate 142 and spacers 144, shown in FIG. 3. Mounted on the guide plate 142 is a support plate 146 on which is mounted a solenoid 150 for holding the gauge arms in an off-center position during the cycle.

Gauge arms 114 and 116 shown in FIGS. 2 and 3 are hinge-mounted on pin 140. The pivotal links 152 and 154 attach to guide arms 114 and 116 respectively by means of pins 156 and 158 and are commonly connected by a guide pin 160. A lock plate 162 is pivotally mounted on a guide pin 166 and is slot-mounted on a stationary anchor pin 164. In the cycle of operations, guide arms 114 and 116 are locked in a separated position by lock plate 162 which is temporarily clamped between the support plate 146 and the upper end of a clamp lever 168 (FIGS. 2 and 3). The lower end of the clamp lever 168 is actuated by a solenoid 156.

Guide plate 142 contains an aperture 172 shown in FIGS. 2 and 4 engaging and guiding the movement of guide pin 16th. The contour of the aperture 172 is of such configuration to provide the proper adjustment of a switch plate 182 shown in FIGS. 4B and 53 as determined by the ratio of the distance from the blade 16 in .FIGS. 1 and 15 to the front ground support to the rear ground support of the ground-engaging means as will be more fully explained. A spring 174 is mounted on guide arm 114 and connecting with guide arm 116 tends to maintain the guide arms in a closed position.

A track bar 186 shown in FIGS. 2 and 3 is secured at both ends to housing 36 and provides one trackway sup port for sliding the switch plates 182 and 184, the opposite track being a groove in guide bar 63. The pivot extensions 1236 and 133 shown in FIG. 3 secured to guide arms 114 and 116 respectively extend downwardly supporting pivotally mounted links 1% and 192 which connect switch plates 182 and 1554 to guide arms 114 and 116, shown in FIGS. 2 and 3. Each end of pivotal links 196 and 15 2 is mounted on hinge pins 1%.

Electric relays 2th 2112, 264, 2 .96, 2%, 219 and 212. shown in lFiGS.-3 and 13, will be explained later.

Starter Lever Assembly The starter lever 4-3 for the control device 45 in FIG. 1 is shown in FIGS. 6 and 7 and is mounted on a pivot 226 which in turn is mounted in upright plates 222 and 224- on base plate 226 as shown in FIG. 6. Fastened to the inner end of pivot 22% is a cam plate 223 (shown in PEG. 7) which has two peripheral lugs 23% and 232 located on opposite sides thereof for actuating the one way switches 234A and 2345 respectively as shown in FIGS. 6, 7 and 13. The one-way switches 234A and 23413 of FIG. 7 have switch arms 236 on the outer end of each of which is a hinge mounted roller assembly 233 biased to a position at right angles to arm 236 by a small torsion spring (not shown), which permits the roller assembly 233 to hinge backward when the roller is contacted in the opposite direction (clockwise relative to switch 234A and counterclockwise relative to switch 234-8), and does not activate the switch on which it is mounted.

At the top of the cam plate 22-h shown in FIGS. 6 and 7 is an extension bar 246 for operating electrical switches mounted on the vertical housing plate 245; which in turn is mounted on the base plate 226. Rotation of the cam plate 228 causes the extension bar 246 to contact a rocker bar 25! of a two-way switch 2% which is mounted on the housing plate 243. Rotation of the cam plate 228 in a clockwise direction also causes bar 246 to depress the switch arm 258 of a double circuit switch 26% mounted on the housing plate 243, whereas rotation of plate 228 in a counterclockwise direction causes bar 246 to depress a switch arm 268 of a double circuit switch 27%) also mounted on the housing plate 248.

The lower surface of the cam plate 22% is a peripheral cam notch 27% shown in PK 7 for centering the starter lever 4-8. The mechanism for urging starter lever 48 to neutral position comprises a roller 28% on one end of a bar 282 which is hinged on a pin 284 which is in turn mounted on the housing plate 224. A compression spring 286 mounted on the base plate 226 presses against the pivotal bar 282, urging the roller 28% upward into the converging faces of the cam notch 2'78 which is the neutral position for the starter lever 48 on the pivot 22%.

On the opposite end or" the pivotal bar 282 is a pin 283 attached to a piston 29%? which operates in a dash pot housing 292 hingedly mounted on the housing plate 224 by a pin 2%. Dash pot 292 contains a spring 2% which urges a ball check 296 against a ball seat 2% in a reservoir 3% in the upper portion of the housing 2&2 shown in PEG. 7. Rotation of the cam plate 228 from neutral position causes the piston 2% to force oil through a restricting orifice 3&2 which retards rotational movement of the cam plate 228. A quick movement of the piston 29% in the opposite direction is permited by oil flowing to the piston through both orifice 3% and the ball checked seat 298 while permitting air to enter the compartment 3% through a vent orifice Mounted on the inner section of the pivot shaft 22%) shown in FIG. 6 is a crank arm 3% having a crank pin 368 to which is pivotally connected an extension rod 311 and a solenoid armature 31b of an overload solenoid 312. Solenoid 312 is mounted on a pivotal base 314 which has a pair of pins 316 pivotally mounted in properly aligned holes in housing plates 222 and 224 respectively. Extending outwardly from the housing plate 222 shown in HS. 6 are two lugs 318 for limiting the movement of the starter lever 68.

The regulator 59 for limiting the vertical speed of the blade to is shown in FIGS. 1, 8 and 9. A pivotal stop member 52, including the lever 32% and member 322, is mounted for rotation in a support bracket 324. A connecting rod 326 pivotally connects the lever 320 with a lever 328 of the opposing rotary stop member 54 mounted on the support bracket 324A. A tension spring 338 is anchored between the pivotal section of the stop member 54- and a pin 331 on the lower section of member 322 in a position suitable to provide an over-center type movement in operation. The upper section of member 322 contains extension pins 332 and 333 properly spaced to provide engagement with an activating lever 334 which is hingedly mounted relative to stop member 52 and pivotally connects to starter lever connecting rod 58.

The operation of starter lever 48 and its several associated components and functions will be brought out below.

Timer Assembly In FIGS. 10 and 11 there is shown the timer unit 30 indicated in FIG. 1. The timer unit 3t includes a housing 336 having an inner housing plate 338 enclosing a rotary cam body 343 having a single lobe 342 and having a friction drive disc 344. The cam 34% is supported in a bushing 345 having a bushing receptacle 347 extending from the housing plate 333 as shown in FIG. 10. The cam body 340 contains a spring 3 58 which presses against a shaft 341 carrying a driving disc 350, said shaft being supported in a bearing 354 mounted in housing 336. v

In the lower end of housing 336 as viewed in FIG. 10 is mounted an electric solenoid 356 which is connected to an actuating lever 358 which is pivotally mounted on a pin 362 supported by the housing 336. When energized, solenoid 356 causes lever 35% to move shaft 352, which carries the cam body 340 longitudinally for engagement with driving disc 356) connected through the shaft 341 with the drive wheel 32 which is in engagement with the adjacent ground wheel 12 shown in FIG. 1.

As viewed in FIG. ll, the direction of rotation of the cam body 340 through its driving connection with the ground wheel of the apparatus is counter-clockwise. When the friction disc 344 is disengaged by the cam 349 to cut off the ground wheel drive connection, the cam 34b is reversely rotated by a torsion spring 362 (shown in PEG. 10) having one end anchored in a recess 364 in the cam shaft 352 and the opposite end pressing against an anchor pin 366 mounted on the housing plate 338. The end of cam lobe 342 is adapted to engage one end of a pivoted stop member 368 best shown in PEG. 11. The stop member 368 is intermediately pivoted at Sit) and the right end of the stop member 368 is urged against a stop bracket 372, mounted on the housing plate 338, by a spring 374 attached to the housing plate 338 and stop member 368 shown in FIG. 11.

A switch plate 38% shown in FIGS. 10 and 11 is mounted for rotation on the cam receptacle 347 between plate housing 333 and a holding collar 382 secured to the receptacle 347. Suitably mounted on the switch plate 38% is a pair of switches 3% and 393 at one point about the cam unit and a second pair of switches 400 and 432 having switch levers 4M and 4% respectively positioned at another point about the cam.

In FIG. 11 the lower segment of the switch plate 389 contains a pin 334 on which is mounted adjustment rod 386 which extends through the housing 336 and pivotally connects to an adjustment lever 388. One end of lever 388 hinges on a pin 3% mounted on a housing lug 392 shown in FIG. 10. Lever 388 and its connecting linkage is for providing an adjustable means to advance the timing of the device for high speed blading operations.

There is a safety switch in FIG. 11 located under stop member 368 and mounted on the plate 338 which is engaged by reverse movement of the stop member 368. A cut-out switch 416, mounted on housing 336 as shown in FIG. 10, is engaged by an arm 412 of a friction drag brake 414 mounted on a driving drum 35% when the drum rotates in reverse direction. A stop lug 416 mounted on housing 336 restricts movement of the arm 412 when the tractor is moving forward.

Overload Control FIG. 12 is a schematic view showing the general features of a tractor engine governor which regulates the amount of fuel supplied to the engine in operation and is well understood in the field. A governor drive shaft 430 mounted on a bearing 432 is gear driven from the tractor engine and rotates hinged linkages 434 carrying flyball weights 436 which are hingedly connected with suitable linkage to a slide member 438. Sliding in a retaining groove 449 of member 438 is a pin 442 mounted on one end of a bell-crank 4 5 which is pivotally mounted on the housing 26, shown also in FIG. 1, by a pin 445. The other end of bell-crank 444 rests against a fuel rod member 346 of a fuel control rod 443. -A spring 450 connects to the fuel rod member 446 and to a bracket 452 mounted on a control rod 454. An overload switch 456 which is a part of this invention and also shown in FIG. 13 is mounted on the control rod bracket ass and is actuated on tractor overloads by a collar 458 mounted on the fuel rod 448. A cut-out switch 460 is mounted on the housing 26 and is opened by the bracket 452 at engine idle speed for breaking the circuit to the overload solenoid 312 of FIG. 13.

Control switch 426 shown in HG. 13 is mounted on the switch panel 42 shown in FIG. 1 and connects the battery to the cut-out switch 410 and rocker actuated switch 254 shown in FIGS. 6 and 13. The overload switch 4-22 connects the battery circuit to the cut-out switch 469 and solenoid switch 456 shown in FIGS. 12 and 13. Switch 424 in FIG. 13 connects the battery circuit to an auxiliary drive mechanism such as shown in P16. 16. Shown in FIG. 13 is a dotted line connecting contact 457 of overload switch 456 to solenoid 64 as an alternate means of enabling the blade 16 to be raised automatically in overload conditions when solenoid 312 is not provided.

Operation Operation of the mechanism will be explained in connection with the mechanical structure described above and with the wiring diagram set forth in FIG. 13.

The blade 16 is initially set at the approximate blading height by the starter lever 48 which activates the tractor hydraulic control valve in a method explained .later, the valving not being shown since it is conventional and well understood in the field.

In the operation of tractor dozing, it is frequently necessary to adjust the depth of blade cut. Starting the blade in the same plane as the tractor ground wheels with all control circuits in open position, the only act which must be performed by the operator is to adjust the blade to the desired depth of cut, which in turn begins the cyclical actuation of the control mechanism and its associated timer and components which will automatically re-adjust the blade properly. The location of the blade forward of the front ground support with respect to the distance between the front and rear ground supports detel-mines the proper amount of blade lowering and raising movement which must take place in a completed cycle. For example, if the tractor front wheels of FIG. 1 are located midway between the rear wheels 12 and blade 15, then the first readjustment of the blade is twice the amount of the initial adjustment and the second re-adjusment is equal the amount of the initial adjustment which was adjusted by the operator. The proportional vertical movement of the blade in its lowering and raising cycle in this invention is governed by the positioning of sliding contact plates 182 and 134 and its connecting linkage of guide arms 114- and 116 which is determined by the configuration of the aperture in guide plate l t-2 shown in FlGS. 2 and 4.

The proper timing of the blade raising and the second blade lowering in the cycle of blade readjustment is essential for obtaining a smooth cut surface in the longi tudinal plane. in the above example, when the blade is lowered in operation it will cut in a plane parallel to the ground plane of the tractor as the tractor progresses forward until the tractor front wheels of PEG. 1 start lowerlng'into the new cut, at which time the blade must be raised in order to compensate for the slightly downward pitch of the tractor. When the rear wheels start lowering into the new cut, the blade must be lowered to the normal ground plane of the tractor within the time that the rear wheels finish lowering into the cut for pro ducing a uniform longitudinal plane. The timing of the lade readjustment in the cycle is determined by the location of the switches mounted on switch plate 369 in FIG. 11 being activated by rotation of cam body 349 of FIG. 10.

T he vertical blade speed is another important factor in obtaining a true blading plane parallel to the plane cut previously to blade adjustment when the blade is located forward of its ground supports. in the foregoing example, the vertical blade speed for the first re-adjustment of the blade must be two times the vertical blade speed of the initial adjustment and the same as the second readjustment of the blade. The pro-per vertical blade speed for each cycle of operations is provided by the regulator Bil shown in FIGS. 1, 8 and 9.

The initial portion of the lowering and raising cycle is determined by the skill of the operator and this skill only need be sufiicient to adjust the blade by lever 43 to the desired depth of cut then release the starter lever. As long as the hand or starter lever 43 is held in a blade adjusting position the blade will move in the desired direction but as soon as the lever 48 is released it will return to a neutral position such as shown in FIG. 7 under the influence of the spring 286, but the control mechansirn and timer will continue to function and re-adjust the blade to return it to the desired blading height automatically.

When the operator desires to increase the depth of blade cut during a blading operation, the hand starter ever 48 is pushed forward which rotates arcuate plate 228 clockwise as viewed in FIG. 7 and closes switch 2343 thus energizing relay 2% shown in FIG. 13 which neutralizes any closed circuits remaining from the previous blade adjustment. Continued rotation of plate 228 permits switch 23413 to close and extension bar 246 depresses one end of over-center type rocker bar 250 of switch 25 closing the circuit to contact 252 and opening contact 256 shown in FlG. 13. Rocker bar 259 remains in one position until it is moved mechanically by starter lever 48 to adjust the blade in the opposite direction. Also, continued rotation of plate 228 activates double circuit switch 2dr) shown in FIGS. 6, 7 and 13 which opens the circuit of solenoid 15% by opening switch lever 262 and simultaneously closing switch lever 26-!- thus energizing relay ZtlZ which closes the circuit of valve solenoid 62 and energizes relay 2% for subsequent action. Energized solenoid 62 activates control valve 61? and causes blade 16 to lower. Movement of hand lever 48 is retarded by resistance of piston 2% and is stopped mechanically by lug 318 on housing 222 shown in PEG. 6.

At the same time, relay 262 shown in FIG. 13 also energizes two other solenoids which continue in holding position for the remainder of the cycle, one being solenoid 139 shown in FIG. 13 which locks gauge frame 11% in the gauge box the other being solenoid 356 of FIG. 10 which activates cam 34% in timer box 38: and starts the cam to rotate. in the meantime, the initial movement of starter lever 43 and rod 58 actuatcs lever 334 of FIG. 8 which is hinged on stop member 52 shown in FIG. 1. if the direction of the initial movement of lever 4% is opposite the direction of the previous initial adjustment of the blade, actuating lever .334 will contact extension pin 332 causing member 322 to start rotating clockwise as viewed in FIG. 3 until holding spring 33% has ceased stretching and starts to contract, whereupon spring ass causes member 322; to continue rotation until it is stopped by link 326 contacting stop member 52-. The mechanism of regulator 56 holds stop members 52 and 54 in one of two positions and in the blade lowering cycle stop member 54 is held. in a horizontal plane whereas stop member 5'2 is held in adown and slope position for the duration of the blade lowering cycle. Member 322 permits starter lever 48 to return to neutral position without changing the position of stops 52 and 54.

Stop members 52. and 54 shown in FIG. 8 are located fore and aft of valve lever 56. in the blade lowering cycle, stop member 52 is adjusted to limit the forward stroke of valve lever as as shown in FIG. 8 resulting in the vertical lowering speed of blade 16 at one half the ola e raising speed without restricting the blade raising operation which is performed automatically in the subsequent re-adiustment cycle by solenoid 6d activating tractor valve 6%. The lowring movement of blade 16 moves cable 33, rod 37 and switch plate on to the right as viewed in FIG. 4. Movement of bar 132 mounted on plate on causes gauge arm 116 to hinge on pin 14% and causes the linkage connected guide pin 16-9 to slide in the aperture 172 of plate 142 which throughconnecting linkage moves switch plate 1E2 to the left.

Release of the starter lever 43 stops the blade lowering and causes the closing switch contact 262 of P16. 11 which is a part of switch unit 269 and this energizes solenoid 155) which locks the gauge arms 114 and 116 in position as shown in FIG. 4. Solenoid 150 remains euergized for the duration or the cycle. In this position, the roller 73 and arm 75 of switch 74 shown in FIG. 4B have moved out of contact with plate 1&2 which results in the closing of switch '74, maintaining a closed circuit to gauge arm solenoid 15%). Relay 2% remains energized through the closed circuit of contact 81 in switch 8t) shown in FiGS. 4A and 13 which maintains a closed circuit to solenoid 136 on gauge frame 110 and solenoid 356 of timer earn 340.

As the cam 34% rotates, it will close switch 396 of FIG. ll and will activate relay 2426' and energize the circuit from said relay to valve solenoid 64 and start to raise the blade 16. The cam solenoid 356, gauge arm solenoid 156, gauge frame solenoid 13d and relay 2% remain energized.

The raising of the blade 16 causes switch plate 66 of gauge box 36 to move switch 8% from contact plate 126 shown in FIG. A which opens the circuit through switch contact 81 of FIG. 13 which de-energizes relay 294; however the circuit for holding relay 2% energized is being maintained by switch '72. When switch plate 65 reaches the position shown in FIG. 5B, switch roller 71 will engage switch plate 132 causing switch 72 to open and break the circuit to relay 2456. This Clo-energizes the blade valve solenoid 6d and stops blade raising movement. At this point, the cam solenoid 356, gauge arm solenoid 150 and gauge frame solenoid 13d remain energized by the circuit through switch contact 83 of of switch also by switch 78 shown in FIG. 13.

The rotating timer earn 346 closes switch to energize the blade lowering valve solenoid so. This solenoid is in circuit with an inactive relay 210 of FIG. 13 and switch 82 due to the closing of the switch 4% which remains closed by the rotating earn.

During this second blade lowering operation, switches 80 and 82 on switch plate 65 are moving toward the center position and when the arms of said switches 3t} and 32, break contact under the contact bar 126 as shown in FIG. 2A, switches 3t) and 82 are opened and all circuits are broken at the instant that spring ball engages in notch 161 of plate 126 shown in FIG. 2C thereby stopping the lowering action of the blade 16. This action deenergizes gauge frame solenoid 153% and gauge arm solenoid 15% which permits gauge arms lid and lid to return to neutral position by spring 178. Since the circult to the cam solenoid 356 is also broken, torsion spring 362 shown in FIG. 16 will cause the cam to return to its starting position as illustratde in FIG. 11. Therefore the blade will remain in a fixed vertical position until the operator or" the tractor is again ready to make another adjustment of the blade.

The right hand portion of the circuit shown in FIG. 13 controls the blade raising cycle and functions in simi lar fashion to that in the left hand side of the diagram. The blade raising cycle is accomplished by pulling the hand lever 43 in the direction opposite to that required for tie lowering cycle described above.

Switch d ll? shown in H63. 10 and 13 is a cut-out switch for preventing the automatic features from functioning when the switch 41% is open. in reverse movement of disc 356, switch ilt? is held in an open position by arm 412 of friction drag brake 4-14 mounted on driving disc 35%. in forward movement of the tractor, switch dill remains closed and arm 412 is restricted from rotation by stop lug 41o mounted in housing 336. This provision enables the operator to back-trowel with the blade without activating the automatic control mechanism.

in the progress of tractor operations, ie tractor load often increases and causes the engine to slow down from its governed speed. In earth blading operations, the operator endeavors to raise the blade when the tractor overloads are encountered to prevent the engine from stalling. This invention provides a means for raising the blade automatically when the tractor encounters overloads. As the tractor engine slows down, the upper portion or" crank 444 moves to the right, as viewed in F1". 12, due to decrease of centrifugal force exerted by the governor flyballs 436 and connecting linkage. During this time, fuel rod 448 and collar 453 are moved to the right by tension of spring 455). Collar 458 closes switch 456 which energizes solenoid 312 shown in FIGS. 6 and 7 which activates lever 48 and causes the blade 16 to start raising. The movement of fuel rod 443 to the right increases the fuel to the tractor engine thereby permitting it to increase its speed which moves the governor linkage to its former setting thus breaking the circuit through switch 4-56 and halting the raising movement of blade 16.

When idling the engine, the operator moves control rod 454 to the left as viewed in FIG. 12 which opens cutout switch see which makes solenoid 312 inoperative.

In MG. 14 is shown a means to regulate the vertical speed of blade 16 hydraulically in cases where installation of a mechanical regulator shown in FIG. 8 is impractical. In the hydraulic line connecting the upper end of cylinder 22 and tractor control valve ell shown in Fit 1 is a solenoid valve 45 shown diagrammatically in FIG. 14 located to permit full flow of oil from cylinder 22 to valve tit) when the valve ind is open. Valve 464 contains a solenoid 4% attached to a poppet valve 4&3 which closes against a seat dlti when solenoid is energized. When solenoid ass is energized during the cycle sequences, oil llow from valve as to cylinder 22 is restricted by flowing through a by-pass channel and orifice 474 and needle stem 4-76 which is adjustable to provide prop-e reduction of lowering speed of blade in.

The hydraulic line connecting the lower section of cylinder 22 to valve 6 3 in FIG. 14 is in circuit with the poppet valve 4655 which contains a solenoid 472 and is a duplicate of valve The circuit for the solenoid as shown in dotted lines in FIG. 13 connects in parallel with valve solenoid also shown in 1, whereas solenoid 472 connects with valve solenoid 64.

In the lowering cycle of blade in, solenoid 46% in MG. 14 closes valve simultaneously with valve solenoid 62 thereby restricting the oil flow from valve 6%? to cylinder 22 and slows the lowering speed of blade id in both the initial lowering and the final re-adjustrnent lowering of the blade to explained previously, but permits full flow or" oil in the opposite direction during the first re-adjust :rent in the cycle when the blade is raising.

In FIG. 15, there is shown tr e adaption of my inven tion wherein the front ground support for the blade during blading operations is a pair of skid shoes and the rear ground support is the tractor. In this arrangement the main blade cylinders 22 attached to tractor ill for aovzesa lifting lade 16 shown in FIGS. 1 and 15 are hydraulically connected to a valve actuated by a hand lever 482 shown in FIG. 15. The main cylinders 22 are used for lifting and lowering the blade 16 and its attached linka e in high lift range for transport but piston rods 24 float freely in cylinders 22 by the proper positioning of valve lever 432 after the blade is lowered for blading operations.

The front ground support mechanisms (the far side not being shown) consists of bell-crank 43d pivotally mounted on blade 16 and connected to ground shoe 486. The upright portion 488 of bell-crank 484 is pivotally connected to the lower end of a piston rod 4% in a cylinder 492, the upper end of the latter being connected to the upper edge of blade 16. Cylinder 492 is hydraulically connected to valve 6% in such manner to cause piston rod 496 to retract into cylinder 492 for lowering the blade 16 with respect to ground support shoe 486, the blade control cycle of operations bein described previously.

Diagrammatically illustrated in EEG. 16 is an auxiliary drive for actuating control lever 56 and valve 6% shown in FIGS. 1 and 16. In this adaptation, valve soleholds 62 and 64 shown in H68. 1, 13, 15 and 16 are mounted on control valve 61 which is also valve 6% of the previous embodiment. A drive motor 498 connects with switch 424 shown in FIG. 13 in dotted lines and connects to a pump 50% which connects with a reservoir -02, control valve 61 and cylinder S d-"t. Piston rod 566 in the cylinder 5ll4 has one end pivotally connected with tractor valve lever 56. Control valve 61, which is actuated by lever 56 and movement of piston rod 5%, controls the vertical movement of blade 16 throughout the cycle of operations as described in the foregoin Various changes may be made in the details of con struction without departing from the spirit or scope of the invention as defined by the claims.

I claim:

1. Earth blading apparatus including an ambulatory frame, ground engaging means supporting said frame, a blade having a support and being connected to said frame for movement between maximum blading limits generally vertically relative to said frame and the ground, said blade having a substantially fixed fore and aft location relative to said ground engaging means, means connected to said blade for raising and lowering the same between said maximum blading limits, and a control device connected with said raising and lowering means and having cyclically operating elements therein for limiting movement of said blade generally vertically through increments of its vertical movement in a cycle in successively opposite directions, and means in said control device connected to and limiting the increments of movement of said raising and lowering device, said movement limiting means being set for operating relative to the fore and aft location of said blade relative to said ground engaging means.

2. Earth blading apparatus including an ambulatory frame, a blade having a support connected to said frame for movement generally vertically between maximum blading limits, means connected to said blade for raising and lowering the blade between said maximum blading limits, and a control device connected with said raising and lowering means and having cyclically operating elements for moving said blade generally vertically through increments of its maximum blading limits in a cycle in successively opposite directions said operating elements being successively movable through a cycle of increments of movement proportional to the initial increments of movement in the cycle.

3. Earth blading apparatus including an ambulatory frame, a blade having a support connected to said frame and movable generally vertically between maximum blading limits, means connected to said blade for raising and lowering the blade between said maximum blading limits, a control device connected with said raising and lowring means and having cyclically operating elements for moving said blade generally vertically through increments of its maximum blading limits in a cycle in sue cessively opposite directions, and said control device including means engaging and movable over the ground with travel of said ambulatory frame and connected to the remainder of said control device for timing the cycle of operation of said cyclically operating elements.

4. Earth blading apparatus including an ambulatory frame, means for moving the frame over the ground, a blade having a support connected to said frame for movement generally vertically between maximum blading limits, means connected to said blade for raising and lowering the blade between said maximum blading limits, a control device connected with said raising and lowering means and having cyclically operating elements for moving said blade generally vertically through increments of its maximum blading limits in a cycle in successively opposite directions, and said control means including a cycle timer connected to said blade raising and lowering means and connected to said means for moving the frame to operate the timer in proportion to the. speed of travel of said frame over the ground. I

5. Earth blading apparatus including an ambulatory frame, means for moving the frame over the ground including ground engaging means supporting said frame fore and aft, a blade having a support connected to said frame for movement between maximum blading limits generally vertically relative to said frame and the ground, means connected to said blade for raising and lowering the same between said maximum blading limits, and a control device connected with said raising and lowering means having cyclically operating elements for limiting movement of said blade generally vertically through increments of its vertical movement in a cycle in successively opposite directions, said control device including a cycle timer connected to said means for moving the frame to operate the timer in increments of vertical blade movement proportional to the fore and aft location of said blade relative to said fore and aft ground engaging means.

6. Earth blading apparatus including an ambulatory frame, means for moving the frame over the ground including ground engaging means supporting said frame, a blade having a support connected to said frame and movable between maximum blading limits generally vertically relative to said frame and the ground, said blade being locat d forwardly of said ground engaging means, means connected to said blade for raising and lowering the same between said maximum blading limits, and a control device connected with said raising and lowering means and having cyclically operating elements for limiting movement of said blade generally vertically through increments of its vertical movement in a cycle in successively opposite directions, and said control device including a cycle timer connected to said means for moving the frame to operate the timer in increments of vertical blade movement proportional to the forward location of said blade relative to said ground engaging means.

7. Earth blading apparatus including an ambulatory frame, a blade having a support connected to said frame for movement between maximum blading limits generally vertically relative to said frame and the ground, raising and lowering means connected to said blade, a timing and a control device connected with said raising and lowering means and including a timer and movement control for said raising and lowering means operatively connected to said blade to move the blade in a timed cycle of opposite alternate increments of its vertical movement, and a starter connected with said control device to initiate its cycle of vertical movement.

8. Earth blading apparatus including an ambulatory frame, a blade having a support connected to said frame for movement between maximum blading limits generally vertically relative to said frame andthe ground, raising and lowering means connected to said blade, a timer and movement control device connected with said raising and lowering means and operable relative to movement of the apparatus over the ground to control the movement of said raising and lowering means and the blade in a timed cycle of opposite alternate increments of its vertical movement, and a starter connected with said control device to initiate its cycle of vertical movement, said starter having a variable interval of activation, the initial blade moving step of the control device in one vertical direction of movement of the blade at the beginning of a timed cycle being controlled by the interval of actuation of the starter, the control device being operable through a complete cycle of increments of vertical blade movement, and means in said control device for completing the cycle of increments of vertical blade movements in proportion to the initial blade movement determined by the starter.

9. Earth blading apparatus including an ambulatory frame, a blade connected to the frame for movement between maximum blading limits and generally vertically relative to said frame and the ground, raising and lowering means connected to said blade, means for initially positioning said blade in a predetermined vertical position relative to the ground, a control device connected to said blade raising and lowering means and operable to move the blade in opposite directions in proportional increments of its maximum vertical movement in a cycle of operation of the control device, and said control device having a variable period starter connected thereto and activated through the first movement of a cycle of blade movements to time the period of said first movement of a cycle of blade movements.

10. Earth blading apparatus according to claim 1 additionally comprising means responsive to a slowing of the apparatus caused by overloading thereof for raising said blade, means for arresting the blade raising when apparatus speed is restored by removal of the overloading on said blade by the raising thereof, and means for automatically initiating a new cycle of blade lowering and raising in response to restoration of normal operating speed of said apparatus.

References Cited in the file of this patent UNITED STATES PATENTS 2,502,217 Guibor Mar. 28, 1950 2,778,130 Gurries et al Ian. 22, 1957 2,965,990 Colee Dec. 27, 1960 3,005,275 Febre Oct. 24, 1961 

2. EARTH BLADING APPARATUS INCLUDING AN AMBULATORY FRAME, A BLADE HAVING A SUPPORT CONNECTED TO SAID FRAME FOR MOVEMENT GENERALLY VERTICALLY BETWEEN MAXIMUM BLADING LIMITS, MEANS CONNECTED TO SAID BLADE FOR RAISING AND LOWERING THE BLADE BETWEEN SAID MAXIMUM BLADING LIMITS, AND A CONTROL DEVICE CONNECTED WITH SAID RAISING AND LOWERING MEANS AND HAVING CYCLICALLY OPERATING ELEMENTS FOR MOVING SAID BLADE GENERALLY VERTICALLY THROUGH INCREMENTS OF ITS MAXIMUM BLADING LIMITS IN A CYCLE IN SUCCESSIVELY OPPOSITE DIRECTIONS SAID OPERATING ELEMENTS BEING SUCCESSIVELY MOVABLE THROUGH A CYCLE OF INCREMENTS OF MOVEMENT PROPORTIONAL TO THE INITIAL INCREMENTS OF MOVEMENT IN THE CYCLE. 